Arthroscopic surgery is an orthopaedic technique consisting of introducing a fiber optic pen-like instrument into a joint, most commonly the knee, to provide a visual image of the surgery site to a video monitor which the surgeon watches to control his instruments within the knee. One of the most common procedures is a meniscectomy, consisting of removing fragments of broken cartilage in the knee, using a surgical cutting instrument called a punch. Arthroscopic surgery is done under a water medium provided by cannulas to pump water into the knee and to outflow the water therefrom.
Punches available today are usually square-shaped and usually cut only one fragment. If the fragments are too big, sometimes the cannulas will get clogged and will need to be cleaned, which wastes valuable surgical time. Another instrument used in meniscectomy is a suction shaver, which is a mechanical instrument which bites and suctions pieces of cartilage. Fragments made from using a prior art punch can sometimes plug the suction shaver. An example of a suction shaver is disclosed in U.S. Pat. No. 5,217,479.
Inflow and outflow cannulas that are inserted above the kneecap can be made larger to accommodate larger fragments generated by prior art punches. However, it is more practical to make cannulas smaller. It is less traumatic for the knee.
Suction shaver used in meniscectomy is typically small in diameter because of the limited space between the femur and the tibia where the instrument is inserted. Additionally, some knees are tight and the maximum suction shaver outside diameter that can be used is about 3.5 mm. If a larger suction shaver is used, the articular cartilage could be damaged, which would be poor surgical technique. Thus, a prior art punch used in this area would typically clog the suction shaver.
There is therefore a need for an arthroscopic surgical punch that will solve the above problems.